Rotary table master bushings



Jill 2, 1957 w. H. SPIRI 2,797,895

ROTARY TABLE MASTER BUSHINGS Filed Sept. 14, 1953 INVEN TOR.

mm H. 5mm,

)f gzw ATTORNEY.

This invention relates to improved master bushing assemblies for use inwell drilling rotary tables.

In drilling a well, it is customary to provide within the rotary table amaster bushing assembly which is adapted to selectively serve as eithera support for a number of pipe gripping slips, or a rotary drivingmember for a kelly bushing. The present invention is concerned with abushing for serving these functions, and which is of a general typecomprising an outer main bushing body, and one or more inner slipsections positionable within the outer body and forming a downwardlytapering bowl for receiving the usual pipe supporting slips. A bushingassembly of this type is shown in copending application Ser. No.371,857, filed July 24, 1953, now Patent No. 2,763,468, on Well DrillingMaster Bushing Assemblies by Walter A. Abegg, and owned by the assigneeof the present invention.

The general object of the present invention is to provide means forpreventing accidental or unwanted movement of the slip bowl sectionsrelative to the outer bushing body in a bushing assembly of the abovetype. More specifically, the bushing may be constructed to positivelyprevent or limit either rotary or upward movement of the bowl sections,and preferably both. As will be understood, it is desirable to preventrotation of the bowl sections relative to the bushing body in order toassure effective transmission of rotary movement from the table to acontained pipe. Further, it is desirable to prevent upward movement ofthe bowl sections, in order to retain them against such movement uponelevation of the contained pipe and slips.

I prefer to so form the movement limiting means as to be easilyreleasable when desired, to thus permit ready removal of the slip bowlsections from the outer bushing body. For this purpose, I may employ alatch or holding element which is movable relative to both the main bodyof the device and its inner slip bowl sections between active andreleased positions. This element may be movably carried by the bushingbody and be engageable with a positioning shoulder or shoulders on thebowl sections. In the preferred form of the invention, the latch elementis movable into an arcuate groove formed in the wall of one or more ofthe slip bowl sections, and acts to limit bowl movement by engagementwith the walls of the groove. For most effective bowl control, two bowlsections are employed, and are individually retained against movementrelative to the bushing body by two separate latch elements carried atdiametrically opposite locations on the body.

The above and other features and objects of the present invention willbe better understood from the following detailed description of thetypical embodiment illustrated in the accompanying drawing, in which:

Fig. 1 is a plan view of a master bushing assembly shown positionedwithin a well drilling rotary table;

Fig. 2 is a section taken on line 22 of Fig. 1;

Fig. 3 is an enlarged vertical sectional view of the bowl lockingmechanism of the invention; and

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Figs. 4 and 5 are fragmentary horizontal sections taken on lines 4-4 and55 of Fig. 3.

In Figs. 1 and 2, I have shown at 10 the central portion of a welldrilling rotary table, containing a vertically extending opening withinwhich is received a master bushing assembly generally indicated at 11.The upper portion 12 of the bushing receiving opening in the rotarytable is square in horizontal section, while the lower portion 13 isvertically cylindrical and of reduced horizontal dimension.

The bushing assembly itself includes an outer one piece rigidessentially annular body section 14, and a pair of complementary innerslip bowl sections 15. In use, the inner slip bowl sections 15 areadapted to receive a pair of conventional slips 16 for gripping andsupporting a pipe 17 within the rotary table. At a pair of diametricallyopposite locations outer body 14 of the bushing carries a pair oflocking units 18 adapted to prevent or limit both upward and rotarymovement of the sections relative to body 14.

Body 14 is shaped externally substantially in correspondence with therotary table opening within which it is received. Thus, body 14 has anupper externally essentially square portion 19 received within squareportion 12 of the rotary table opening, and has a lower essentiallycylindrical portion 20 engaging cylindrical portion 13 of the table. Theupper square portion 19 of body 14 may be cut off at an angle at itscorners 21, as shown. Extending between its upper square and lowercylindrical portions, table 10 has an annular horizontal shoulder 22engaging a shoulder 23 on body 14 to positively support the body withinthe table. The body shoulder 23 is essentially annular and facesdownwardly and is interrupted only at the locations of locking units 18.

The bowl engaging portion of body 14 has a pair of inner cylindricalsurfaces 24 and 24a, the upper of which is of a diameter somewhatgreater than the lower, and between which is formed an annularxnpwardlyfacing horizontal shoulder 25 for engaging a corresponding shoulder onthe slip bowl sections to support those sections in the body. The twobowl sections 15 are horizontally semi-circular and havesemi-cylindrical outer surfaces engaging surfaces 24 and 24a in body 14.The surfaces within bowl sections 15 form together a downwardly taperingor converging recess 26 for receiving the conventional slips 16.

Above bowl sections 15, the vertical opening through body 14 has anupper non-circular portion 27 for receiving and driving a conventionalkelly bushing. In accordance with the usual practice of forming thekelly bushing to be externally essentially square, this upper portion 27of the body opening may be correspondingly essentially square, and forthat purpose may have corner portions 28 projecting radially outwardlyfrom four evenly spaced locations about the body opening, to receive thefour corners respectively of a kelly bushing. If desired, these cornerportions 28 of the upper non-circular part of the body opening may besomewhat enlarged at their exact corners 29, as shown.

Each of the lock units 18 includes a lock element 35) which is mountedwithin a horizontally extending opening 31 in body 14 for horizontalmovement between the full line and broken line positions of Fig. 4. Thetwo elements 30 are positioned at diametrically opposite locations andhave inner slightly tapering portions 32 which are movable into and outof arcuate outwardly and upwardly opening recesses 33 in the upper endportions of the outer walls of slip bowl sections 15. These recesses 33form together an essentially annular recess, which is interrupted at anumber of evenly circularly spaced locations by portions 34 of the slipbowl sections extending out to the full diameter of the sections. Aswill be understood, the inner portions 32 'of lock elements 30, when intheir full line Fig. 4 positions, are'engageable by pertions orshoulders 34 of the slip bowl sections to positively limit rotarymovement of the bowl sections within body 14. 'Also, engagement of lockelement portions 32 with bottom walls 35 of recesses 33 acts to preventupward withdrawal of the bowl sections from body 14.

' Lock elements 32 are actuable horizontally between their active andreleased positions by means of a pair of operating members 36, which aremounted for rotation about vertical axes by reception of theircylindrical portions 37 within vertical bores 38 in the body. A pair ofretaining screws 137, threadedly and removably connected into body 14,engage upper annular surfaces 138 of cylindrical portions 37 of themembers 36, to releasably retain members 36 against upward withdrawal,while permitting rotation of these members. Members 36'have lowercylindrical portions 39 which are positioned eccentrically with respectto the axes of rotation of members 36, and are movably received withinlaterally elongated openings 40 in lock elements 30. As will beappreciated, rotation of one of the members 36 about its vertical axisacts to swing the lower portion 39 of that member eccentrically in amanner moving one of the lock elements 30 between its full line andbroken line positions of Fig. 4. Preferably, 180 swinging movement ofmember 36 acts to move the portions 39 thereof between its two activeand released positions.

Each of the members 36 has at its upper end a portion 42 of anon-circular (typically square) section, about which is received atubular sleeve 43 which is internally of corresponding non-circularconfiguration, so that the sleeve is movable vertically relative tomember 36, but is adapted to turn member 36 about its axis. Sleeve 43carries a diametrically extending handle element 44, by which the sleeveis movable vertically between the elevated broken line position of Fig.3, in which the handle is rotatable, and the lowered full line position.Such vertical movement is limited at the illustrated full line andbroken line positions by engagement of a pin 45, fixed to and extendingtransversely through sleeve 43, with the ends of a vertically extendingrecess 46 formed in the side of member 36. In the lowered full lineposition of each handle, the ends of handle element44 are receivablewithin a recess 47 in the upper surface of body 14. This recess. is soshaped as to receive the handle element in either of two rotarypositions relatively ofi'set 180, but not in intermediate positions, tothereby positively lock the handle and member 36 in either the activeposition or retracted position of element 30.

In using the illustrated master bushing assembly, the various parts willnormally be positioned as shown in the figures, with elements 30projecting into recesses 33 in bowl sections 15, to lock the bowlsections against upward withdrawal from body 14 and to limit rotation ofthe bowl sections within the body. Rotary movement may. thus betransmitted from body 14 tobowl sections 15 for rotating pipe 17 bymeans of the rotary table. At the same time, the retention of bowlsections 15 against upward withdrawal prevents their upwardmovementwithslips 16 when the slips are being removed from the bowl to. release thegrip on pipet17.

When the table is being used to turn a drill string by action against akelly, the slips 16 are removed from bowl sections 15, and the squareportion of a kelly bushing is received within the uppernon-circularportion 27 of master. bushing body 14. If the occasion arises forpassing a drilling bit or other enlarged element through the masterbushing, handles 44 are elevated to their broken line positions of Fig.3, following which they are rotated to release lock elements 32 andpermitupward withdrawal of bowl sections 15, thus enlarging' the openingwithin the bushing assembly for passing the bit or other member. Forfacilitating such removal of bowl sections 15, eachof .thesesectionsmay'have a pair of passages 48; extending. through its. side :-:wall,':'and ;.into

which a hook or other tool may be inserted to lift the section outof-the bushing body. A pair of similar diametrically opposite openings49 may be formed in body 14 of the bushing assembly.

I claim:

1. A well-drilling master bushing assembly comprising an outer rigidbody adapted to be received and supported in a rotary table recess andcontaining an opening extending vertically therethrough, said bodyhaving an upper externally non-circular portion to be received andsupported in and rotatably driven by an upper non-circular portion ofsaid rotary table recess, said body having a lower portion of externallyreduced dimension extending downwardly into a lower portion of saidrotary table recess, said upper non-circular portion of the bodyextending laterally beyond said lower portion, and a plurality of slipbowl segments supported in a lower portion of said body opening andhaving downwardly converging inner slip engaging surfaces, means forsupporting said slip bowl segments in said'body, said outer bodycomprising a onepiece rigid member which is circularly continuousentirely about said opening so that lateral expanding forces exertedagainst the. body are taken directly by it without transmission to therotary table, said slip bowl segments being completely removableupwardly from said outer body to pass a drill bit through the body, thematerial of said body forming a non-circular upper portion of saidopening adapted to receive and directly engage and rotatably'drive amating non-circular portion of a kelly bushing, said slip bowl segmentsbeing positioned low enough in the body to allow reception of saidnon-circular portionof the kelly bushing in said upper non-circularportion ofjthe body opening in direct rotary driving engagement with thebody at that location without removal of the slip bowl segments from thebody, a lock element, means movably mounting said lock element to saidbody at a location laterally, opposite one of said slip bowl segmentsand for movement relative to the body between activeand releasedpositions, a shoulder on said one segment movable along a path in a.predetermined direction upon predetermined displacement of the slip bowlsegment, said lock element in said active'position being located in saidpath .of movement of said shoulder and thereby acting to hold said onesegment against said predetermined displacement, said lock element inreleased position being out of said path to release the segment for saiddisplacement, said shoulder facing at least partially in said direction,said means movably mounting the lock element including means holding thelock element against movement in said direction relaive to the body insaid active position, a movable actuating member supported in'andextending upwardly through said upper non-circular portion of the bodyand extending upwardly beyondsaid slip bowl segments and horizontallyopposite said upper non-circular portion of said opening,-an operatingconnection between said actuating member and said locking element foractuating said lockingvelement between said active and releasedpositions in accordance with movements of the actuating member, a handlemounted for movement relative to the body at the upper end .of saidactuating member and manually operable from the upper end of said body,and a connection between said handle and said actuating member forvactuating the member and lock element in accordance with movements ofthe handle.

2. A well-drilling master bushing assembly as recited in. claim 1,including means mounting said handle for manual rotation toactuate saidlock element and for axial movement relative to said body between anupper position and a lower position, there being a shoulder on said-bodypositioned in the rotary path of the handle in said lower position ofthe handle but not in said upper position andjthereby acting to retainthe handle against rotation foractuating the locking element in saidlower position.

3. A well-drilling master bushing assembly as recited in claim 1, inwhich there are two of said handles, two actuating members, and twolocking elements carried by the body, for engaging two of said slip bowlsegments respectively.

4. A Well-drilling master bushing assembly as recited in claim 1, inwhich said locking element and said shoulder on said one segment areengageable to releasably retain the segment against upward movementrelative to said body.

5. A well-drilling master bushing assembly as recited in claim 1, inwhich said locking element and said shoulder on said one segment areengageable to releasably retain the segment against upward movementrelative to said body, said one segment having an additional shoulderengageable by said lock element to prevent rotary movement of said onesegment relative to the body.

6. A well-drilling master bushing assembly as recited in claim 1, inwhich said lock element is movable horizontally relative to said bodybetween a locked position and a released position, said actuating memberand handle being mounted to said body for rotary movement aboutessentially an upwardly extending axis, said member hav- 6 ing a portionat its lower end positioned eccentrically with respect to said axis andreceived within a recess in said lock element to actuate it between saidlocked and released positions in accordance with rotary movement of saidmember and handle.

References Cited in the file of this patent UNITED STATES PATENTS277,398 Wise May 8, 1883 1,506,583 Hoffman Aug. 26, 1924 1,507,325Reynolds Sept. 2, 1924 1,513,388 Greve Oct. 28, 1924 1,679,955Bartholomew Aug. 7, 1928 1,771,391 Black July 29, 1930 2,008,774Spalding July 23, 1935 2,030,318 Pranger et al. Feb. 11, 1936 2,115,279Pennington Apr. 26, 1938 2,182,793 Davidson Dec. 12, 1939 2,282,617Spalding May 12, 1942 2,422,383 Young June 17, 1947 Pearce Nov. 20, 1951

